scholarly journals Aqueous Sol-Gel Derived Nanocomposite Coating Materials

1998 ◽  
Vol 519 ◽  
Author(s):  
H.K. Schmidt ◽  
E. Arpac ◽  
H. Schirra ◽  
S. Sepeur ◽  
G. Jonschker ◽  
...  
Keyword(s):  
Condensation Reaction ◽  
Sol Gel ◽  
Particle Interaction ◽  
Nanocomposite Coating ◽  
Vapor Concentration ◽  
Coating Materials ◽  
Solvent Vapor ◽  
Water As Solvent ◽  
Hydrolysis And Condensation ◽  
Surface Modified

AbstractSol-gel reactions, in general, have to take place in organic solvents in order to control the hydrolysis and condensation reaction. This leads to drawbacks in applications, since the organic solvent vapor concentration has to be controlled for example in coating applications for environmental, health or security reasons. For this reason, a reaction route has been developed to produce coating precursors stable against water as solvent. To achieve this, conventional electrostatically stabilized sols obtained either by hydrolysis and condensation or commercially available sols (e.g. SiO2sols) have been surface-modified to reduce the particle-to-particle interaction and electrosterically stabilized precursors compatible to water have been obtained. By use of alkoxy silanes as surface modifiers, water-dispersable nanoparticulate liquid coating systems have been prepared, for example, with boehmite, SiO2 or TiO2 as nanoparticles to be crosslinked after coating thermally by inorganic condensation and organic condensation or polymerization reactions. Thus, aqueous sol-gel coating systems have been prepared with EtOH contents below 5 %. In the paper, the basic reaction as well as material properties will be discussed.

Fabrication and Microstructure of ZnO-SiO2 Nanoparticles by a Reverse Micelle and Sol-Gel Processing

2006 ◽  
Vol 510-511 ◽  
pp. 790-793 ◽  
Author(s):  
Rak Hee Kim ◽  
Jae Won Kim ◽  
K.S. Park ◽  
Dong Sik Bae
Keyword(s):  
Reverse Micelle ◽  
Condensation Reaction ◽  
Sol Gel ◽  
Sio2 Nanoparticles ◽  
Molar Ratio ◽  
Metal Alkoxide ◽  
Hydrolysis And Condensation ◽  
Micro Emulsion ◽  
Average Size ◽  
Gel Processing

ZnO-SiO2 nanoparticles were synthesized using a reverse micelle technique combined with metal alkoxide hydrolysis and condensation. The size of the particles was controlled by manipulating the relative rates of the hydrolysis and condensation reaction of tetraethyl orthosilicate (TEOS) within the micro-emulsion. The average size of synthesized ZnO-SiO2 nanoparticles was in the range of 20-40 nm. The effects of synthesis parameters such as the molar ratio of water to precursor and the molar ratio of water to surfactant are discussed.

Synthesis and Microstructure of TiO2-SiO2 Nanoparticles by a Reverse Micelle and Sol-Gel Processing

2006 ◽  
Vol 317-318 ◽  
pp. 227-230
Author(s):  
Dong Sik Bae ◽  
Byung Ik Kim ◽  
Kyong Sop Han ◽  
James H. Adair
Keyword(s):  
Reverse Micelle ◽  
Condensation Reaction ◽  
Sol Gel ◽  
Sio2 Nanoparticles ◽  
Titanium Isopropoxide ◽  
Molar Ratio ◽  
Metal Alkoxide ◽  
Hydrolysis And Condensation ◽  
Micro Emulsion ◽  
Average Size

TiO2-SiO2 nanoparticles have been synthesized using a reverse micelle technique combined with metal alkoxide hydrolysis and condensation. The size of the particles can be controlled by manipulating the relative rates of the hydrolysis and condensation reaction of tetraethyl orthosilicate (TEOS) and titanium isopropoxide (TIP) within the micro-emulsion. The average size of synthesized TiO2-SiO2 nanoparticles was about in the size range of 20-100 nm. The effects of synthesis parameters, such as the molar ratio of water to precursor and the molar ratio of water to surfactant, are discussed.

Synthesis and Microstructure of Al2O3-SiO2 Nanoparticles by a Sol-Gel Processing

2007 ◽  
Vol 124-126 ◽  
pp. 679-682 ◽  
Author(s):  
Sung Kang ◽  
Byung Ik Kim ◽  
Chang Yeoul Kim ◽  
Jong Kyu Lee ◽  
Dong Sik Bae
Keyword(s):  
Size Range ◽  
Condensation Reaction ◽  
Sol Gel ◽  
Sio2 Nanoparticles ◽  
Molar Ratio ◽  
Synthesis Parameters ◽  
Stirring Rate ◽  
Hydrolysis And Condensation ◽  
Average Size ◽  
Gel Processing

Al2O3-SiO2 nanoparticles have been synthesized by a sol-gel processing. Size and composition of the synthesized particles can be controlled by manipulating the relative rates of the hydrolysis and condensation reaction of precursor. The average size of synthesized Al2O3-SiO2 nanoparticles was about in the size range of 50~100nm. The effects of synthesis parameters, such as the molar ratio of water to precursor, the molar ratio of water to surfactant and stirring rate, are discussed.

scholarly journals FLUORESCENCE STUDIES FOR IN SITU MONITORING OF THE HYDROLYSIS AND POLYMERIZATION REACTIONS OF ORGANICALLY –MODIFIED TETRAMETHYLORTHOSILICATE

2010 ◽  
Vol 5 (3) ◽  
pp. 290-294
Author(s):  
Eko Sri Kunarti
Keyword(s):  
Condensation Reaction ◽  
Sol Gel ◽  
In Situ Monitoring ◽  
Condensation Polymerization ◽  
Surrounding Water ◽  
Fluorescence Studies ◽  
Hydrolysis And Condensation ◽  
Organically Modified ◽  
Kinetics Of

Monitoring of hydrolysis and condensation polymerization reactions of tetramethylorthosilicate-organosiloxane have been carried out. Proton transfer from the excited state of 8-hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt (pyranine) to surrounding water molecules was used as a sensitive fluorescence method for following the kinetics of water consumption during the early stages of the sol-gel polymerisation process. Changes in water/silane ratio, type of organosiloxane, mol ratio of organosiloxane to silica precursor and pH affected markedly the kinetic behavior of the hydrolysis and condensation reaction of tetramethylorthosilicate.   Keywords: hydrolysis, polymerisation, fluorescence, pyranine, tetramethylorthosilicate, organosiloxane.

scholarly journals Hard Coating Materials Based on Photo-Reactive Silsesquioxane for Flexible Application: Improvement of Flexible and Hardness Properties by High Molecular Weight

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1564
Author(s):  
Jong Tae Leem ◽  
Woong Cheol Seok ◽  
Ji Beom Yoo ◽  
Sangkug Lee ◽  
Ho Jun Song
Keyword(s):  
Molecular Weight ◽  
Surface Morphology ◽  
High Molecular Weight ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Coating Materials ◽  
Pencil Hardness ◽  
Coated Film ◽  
Flexible Application

EPOSS of polyhedral oligomeric silsesquioxanes (POSS) mixture structure and LPSQ of ladder-like polysilsesquioxane (LPSQ) structure were synthesized via sol–gel reaction. EPSQ had a high molecular weight due to polycondensation by potassium carbonate. The EPSQ film showed uniform surface morphology due to regular double-stranded structure. In contrast, the EPOSS-coated film showed nonuniform surface morphology due to strong aggregation. Due to the aggregation, the EPOSS film had shorter d-spacing (d1) than the EPSQ film in XRD analysis. In pencil hardness and nanoindentation analysis, EPSQ film showed higher hardness than the EPOSS film due to regular double-stranded structure. In addition, in the in-folding (r = 0.5 mm) and out-folding (r = 5 mm) tests, the EPSQ film did not crack unlike the EPOSS coated film.

scholarly journals Oxazoline-based crosslinking reaction for coatings

2021 ◽  
Author(s):  
Philipp Knospe ◽  
Patrick Böhm ◽  
Jochen Gutmann ◽  
Michael Dornbusch
Keyword(s):  
Mechanical Properties ◽  
Loss Modulus ◽  
New Technology ◽  
Sol Gel ◽  
Polymer Network ◽  
Time Dependent ◽  
Crosslinking Reaction ◽  
Coating Materials ◽  
Rheological Measurements ◽  
Excellent Adhesion

AbstractNowadays, coating materials must meet high demands in terms of mechanical, chemical and optical properties in all areas of application. Amongst others, amines and isocyanates are used as crosslinking components for curing reactions, meeting the highly demanding properties of the coatings industry. In this work, a new crosslinking reaction for coatings based on oxazoline chemistry is investigated with the objective to overcome disadvantages of established systems and fulfill the need for sustainable coating compounds. The oxazoline-group containing resin, synthesized from commercially available substances, undergoes cationic self-crosslinking polymerization to build up a network based on urethane and amide moieties. NMR-, IR- and ES-mass spectroscopy are suitable techniques to characterize the synthesized oxazoline monomers, which are linked to polyisocyanates and polymerized afterwards via self-polymerization. The progress of crosslinking is followed by changes in IR spectra and by rheological measurements to calculate time dependent values for storage and loss modulus. The glass transition temperature of the resulting coating is determined, too. Furthermore, sol–gel-analysis is performed to determine the degree of crosslinking. After application on steel and aluminium panels, application tests are performed. In addition to excellent adhesion to the substrate, the polymer network shows promising mechanical properties and with that it could represent a new technology for the coatings industry.

Preparation and characterization of a novel nanocomposite coating based on sol-gel titania/hydroxyapatite for solid-phase microextraction

2019 ◽  
Vol 145 ◽  
pp. 942-950 ◽  
Author(s):  
Fereidoon Rahmani ◽  
Ali Es-haghi ◽  
Mohammad-Reza Milani Hosseini ◽  
Afsaneh Mollahosseini
Keyword(s):  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Sol Gel ◽  
Nanocomposite Coating

Organic–inorganic hybrids having a talc-like structure as suitable hosts to guest a wide range of species

2018 ◽  
Vol 47 (9) ◽  
pp. 2925-2932 ◽  
Author(s):  
J. Brendlé
Keyword(s):  
Hybrid Materials ◽  
Sol Gel ◽  
Step Method ◽  
Mild Conditions ◽  
Condensation Reactions ◽  
Wide Range ◽  
Sol Gel Process ◽  
Hydrolysis And Condensation ◽  
One Step

The sol–gel process involving hydrolysis and condensation reactions is an attractive way to form siloxane based hybrid materials since it is a one-step method performed under mild conditions.

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